Hot-air furnace.



W. U. H. NOBLE.

HOT AIR FURNACE.

APPLICATION FILED MAY 4, 1910 1,01 3,304. Patented Jan. 2, 1912.

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COLUMBIA I'LANUGIMIN (10., WASHINKTI'ON. u. c.

W. G. H. NOBLE.

HOT AIR FURNACE.

APPLICATION FILED MAY 4, 1910.

1,01 3,304, Patented Jan. 2, 1912.

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WILLIAM C. H. NOBLE, F LOS ANGELES, CALIFORNIA.

HOT-AIR- FURNACE.

Specification of Letters Patent.

Patented Jan. 2, 1912.

Application filed May 4, 1910. Serial No. 559,391.

To all whom it may concern:

Be it known that I, WILLIAM C. H. NOBLE, a citizen of the United States, residing at Los Angeles, in the county of Los Angeles and Stateof California, have invented a new and useful Hot-Air Furnace, of which the following is a specification.

This invention relates to flurnaces for heating air for warming buildings, etc, and the main object of the invention is to provide a heater which is of simple and cheap construction and which will be durable and eflicient in operation.

Another object of the invention is to provide an improved construction of the shell or body of the heater whereby it is adapted to sustain the strains and retain its form under the high temperatures which are liable to occur in operation of the heater.

In hot air furnaces of large capacity the use of a cylindrical shell is open to the objection that the top of the shell is liable to sag when the metal becomes more or less softened by the intense heat of the furnace and the invention is directed particularly to overcoming this difliculty by providing a furnace shell which will present maximum rigidity and strength in a vertical direction so as to resist such collapsing action.

Another object of the invention is to pro vide a furnace shell which will be gas tight, and will retain its gas tight condition under the high temperatures and strains involved in its operation.

' A further object of the invention is to provide improved means for radiating or carrying away the heat from the shell to the body of air surrounding the same.

Other objects of the invention will appear hereinafter.

The accompanying drawings illustrate the invention, and referring thereto:

Figure 1 is a side elevation of the furnace, partly broken away, Fig. 2. is a cross section on the line w -00 in Fig. 1. Fig. 8 is a cross section on the line w x in Fig. 1. Fig. 4 is a rear end elevation of the furnace. Fig. 5 is a side elevation of one of the clamping straps for the radiating ribs. Fig. 6 is a perspective of the radiating or heat conducting ribs.

The furnace comprises a shell or body 1 mounted on bases or supports 2. The shell or body 1 is of substantially oval cross section with the longer axis of the oval clirected vertically and the more pointed end ends to two side members 10, said side members being bent toward one another and brought together at an angle with a vertical flanged seam 12 at the top. The joints between the side members 10 and the bottom member 9 are formed by flanging the said members outwardly, as shown at 11 and riveting or otherwise securing such flanged portions together. The front and rear end plates 14 and 15 for the shell are formed of approximately elliptical shape semicircular at the bottomv and pointed at the top and conforming to the inside of the metal shell 10, said end members being flanged on their outer faces and the shell being riveted to such flanges, as shown at 16. All of the seams for connecting the shell plates to one another and to the end plates are external or extend out from the body of the shell, thereby removing them from the heat. By this means, and by using sheet iron instead of cast iron for the sections, I am enabled to maintain a gas tight joint.

The front head 14 is provided with a tubular member 17 for a fire door 18 and with a tubular member 19 for an ash door 20, said door 20 also serving as the air admission means and said doors 18 and 20 being located in the front plate 21 of the furnace.

The rear head 15 is provided in its lower portion with an outlet member 23 formed as an elbow having two branches 23 communicating respectively with upwardly extending tubes 24. which connect at their upper ends by elbows 25 with pipes 26 extending longitudinally over the body of the furnace and communicate at their forward ends with a smoke box 27. An elbow 28 mounted on top of said smoke box may be connected to a return flue 29 extending back over the furnace shell for communication to a stack at the rear of the furnace, or, if desired, may be turned forwardly for communication to a stack at the front of the furnace.

A grate 30 divides the space within the shell into a combustion chamber above the grate and an ash pit below the grate, said ash pit serving for air admission through the ash door and being closed at the rear end by a partition plate 50. The grate 80 is supported on side rails 31 and cross rail 32 within the furnace body and a bridge wall 33 is also supported on said cross rail causing the products of combustion to pass upwardly over said bridge wall ,before they are passed downwardly into the outlet 23.

Means are provided for increasing the radiating or heat conducting capacity of the walls of the shell 1, said means consisting of hollow rib members 40, each formed of sheet metal bent in the form of a semi-tubular member U-shaped in cross section and open at one side, said open side being curved to fit the curved side walls 10 of the shell and the edges at such opened side being bentover or flanged, as at 42, see Fig. 6. These rib members are supported on the shell 1 by means of a saddle 43 resting on the seam 12 at the top of the shell and strap means 44 secured to said saddle and extending through and in contact with said semi-tubular rib members and tension straps 46 secured to the lower end of said strap means and passing through perforations in the saddle 47 below the shell member 9. Said strap means 44 are provided with eyes 45 at their upper and lower ends to receive pins 45 for.

fastening said ends respectively to the saddle 43 and to the tension straps 46. Springs 48 are provided on the lower ends of said straps 46, said springs engaging with the saddle 47 and with nutsor heads 49 on said straps 46 to tension the straps and at the same time provide for the expansion and contraction of the parts in the heating and cooling of the furnace.

The furnace above described is especially adapted and intended for use with forced draft systems wherein the air which is heated by the furnace, is forced through the building to be heated instead of depending on natural draft. With such forced draft the furnace requires to be of great heat transmitting capacity so as to effectually heat the large quantities of air passing through the system at a rapid rate. This large and rapid heating capacity is effected by the radiatlng means shown and described, and the special construction of the shell above described enables me to attain the high temperature requisite for effectually heating such large quantities or air without" by the means of the standing seams on the sheet metal, said joints may be riveted, so

that a permanent air tight fit is insured.

any inward leakage of air from the plenum causing violent fluctuations in the firing, and excessive heating of the plates. Said standing seams also present the advantage that the joints are thereby removed from the direct heat of the fire. In this connection an important feature of the invention is the construction of the plates with a single joint at the top, the plates forming an angle at the top so as to permit of such joint with a single plate at each side and a single plate at the bottom jointed to the side plates with a single standing seam at each side. The number of joints is thus reduced to a minimum and all of the seams are on the outside.

What I claim is:

1. In a hot air furnace, a shell formed of a plurality of sections of substantially oval shape having their edges secured together, each section consisting of a lower member bent in approximately semi-circular shape and two side members connected respectively to the ends of the said lower member, said side members and lower member havingoutwardly extending flanges for connecting them together, and said side members extending upwardly from the ends of said lower member and meeting at an acute angle at the top and being extended at the top to form a joint, means securing said joint portions together, and substantially oval end plates closing the-ends of the shell.

2.- In a hot air furnace, the combination with the shell forming the combustion chamber, of radiator means therefor comprising hollow rib members resting against the sides of said shell, said hollow ribmembers being open at the side toward the shell and having flanges resting against the shell, and means for detachably securing said hollow rib members to said shell, comprising straps extending within said hollow rib members and engaging said flanges thereon, means resting on the top of the shell and connected to said straps, means for supporting said straps at the upper end of said shell and means for tensioning said straps at the lower end of said shell.

3. In a hot air furnace, the combination with the shell forming the combustion chamber of radiator means therefor, comprising hollow rib members resting against the sides of said shell, .and means for detachably securing said hollow rib members to said shell, comprising straps extending within and engaging said hollow rib members, means forsupporting said straps at the upper end of said shell, and means for tensioning said straps at the lower end of said shell, said tensioning means comprising springs exert- 5 ing elastic tension on said straps to provide for expansion and contraction.

4:- In a hot air furnace, a sheet metal shell having a rounded contour, rib members resting on said shell and having flanged por- 10 tions rounded longitudinally to conform to the shell, and straps engaging said flanged portions to hold said rib members in contact With the shell. 7

In testimony whereof, I have hereunto so my hand at Los Angeles California this 5 27th day of April 1910.

WILLIAM C. H. NOBLE. In presence of ARTHUR P. KNIGHT,

FRANK L. A. GRAHAM.

Copies of this patent may be obtained for five cents each, by addressing the "Commissioner of Patents,

Washington, D. G. 

